The electrical fuel injector of this type is disclosed, for example, in Japanese Patent Laid Open No. 56-24522 "Basic Pulse Computing Method and Apparatus for Hot-Wire Type Flow Meter" distributed on Mar. 9, 1981.
In this known fuel injector, in order to control an opening time of an injection valve without suffering any influence from an amount of air intake to an internal combustion engine, an air-intake amount detection signal is input to an electronic circuit through a digital filter having a constant coefficient and then an opening time of the injection valve is computed. According to this known fuel injector, however, since the detection signal for the amount of air intake to the internal combustion engine is input to the electronic circuit for computing the opening time of the injection valve through the digital filter having a constant coefficient at all times regardless of the revolution count and load of the internal combustion engine, there arises such a drawback that a rising characteristic of the revolution count is impaired.